JPH05161520A - Chair and controller and base part cover assembly thereof - Google Patents

Abstract

PURPOSE: To relieve or eliminate a problem of 'cramping of a shirt' by providing a mechanism to control back rest inclination larger than seat inclination on a chair having a separated back rest and a support body of a seat. CONSTITUTION: When a user throws back his/her head on a chair, a back rest support body 38 is energized downward against a flipper 40 in an interface C and rotates the flipper 40 around a shaft D as its center. That is, at a position inclined backward, the flipper 40 is deflected downward. When the flipper 40 is deflected downward, a seat support body 36 is rotated in a specified relation around a seat pivot shaft A as its center by vertical reciprocal engagement by a pin 60 between the seat support body 36 and the flipper 40. Angular motion of the flipper 40 due to a difference each of radi between results D-E, A-E of the same vertical motion of the flipper 40 and a rear part of a seat at a reciprocal connecting part E or effective length of a link becomes actually larger than angular motion of the seat support body 36. In the same way, the flipper 40 extensively and vertically displaces a support body at a C position rather than a rear end part of the seat support body 36 at an E position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backrest, a seat, and a tilted back chair of the type having a base. More particularly, the present invention relates to improved chairs and controls suitable for office and other environments.

[0002]

2. Description of the Related Art Conventionally, a chair can be moved in accordance with a user's movement, and the problem of "shirt pull", which has been found in many chairs in the past, can be reduced and is simple and reliable. Many attempts have been made to provide certain chairs and controls. Twitching of a shirt is a phenomenon that occurs in chairs in which the back of the chair moves the user's back up and up when the user tilts the chair backwards, pulling the shirt out of its normal waist-holding position. Another problem with chairs is when the backrest and seat tilt at substantially the same rate, ie, the degree of backrest tilt and seat tilt are substantially the same. In such a chair, when the user turns over, the front part of the seat urges behind the upper leg of the user, which is uncomfortable and at the same time impairs blood circulation in the user's leg. In addition, the user loses stability when the user's weight is rearward. Therefore, a chair in which the backrest and the seat are tilted separately is desired. More specifically, a chair in which the degree of inclination of the backrest is sufficiently larger than the degree of inclination of the seat when the user leans back is desirable. Furthermore, it is desirable for the seat to have the flexibility to independently support the user, especially at the front of the seat, and to accommodate the user in a variety of typical postures. The seat of the chair, for example, is inclined to the left and right, one leg is extended from the other,
Alternatively, it may be adapted to the user's legs with both legs extended without unduly applying local pressure. For this purpose, it is desirable that the seat of the chair provides a twisting (left and right) bending of the front portion thereof and a vertical elasticity of the front portion matching the flexibility of the front-rear pitch. Further, it is desirable to provide a finished, integrated, smooth surfaced bearing and support. Although chairs have been proposed in the direction of having the various properties described above, an improved design that economically provides the above properties in an efficient manner is desired.

The present invention seeks a differential tilt, ie, a backrest tilt greater than the seat tilt, in a chair having a separate backrest and seat support. The chair control mechanism of the present invention is designed to coordinate back and seat movements with the user's natural sitting and half-tilt movements. Moreover, it alleviates the problem of shirt pulling that is present in many conventional chairs. Further, it provides a chair that allows both twisting and vertical distortion in the front of the seat to comfortably accommodate various typical postures of the user. Further, the advantages of the illustrated embodiment of the invention include the Faultless, Evansville, Indiana
It can be manufactured economically by retrofitting existing chair controls, such as Caster's known controls.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved chair design with the desirable characteristics described above. It is a further object of the present invention to provide an improved chair with a backrest and seat tilting in independent proportions. Yet another object of the present invention is to provide an improved chair control which controls a backrest tilt greater than the degree of seat tilt. Yet another object of the present invention is to alleviate or eliminate the conventional problem of "shirt pulling". Yet another object of the present invention is to provide a chair that exercises in cooperation with the natural movements of the user. Yet another object of the present invention is to provide a chair that is attractive in appearance and relatively simple to manufacture. Furthermore, other objects of the invention will be apparent from the following description and claims with reference to the accompanying drawings.

[0005]

The above and other objects are achieved by a chair having a base, a vertical post supported by the base, a chair seat having a rear portion and a front portion, a chair back, and a chair control device. The chair controller has a housing pivotally mounted to the vertical post for holding in a predetermined standard horizontal plane, elastic biasing means mounted within the housing, seat supports, back supports, and back frames. It consists of members or flippers. The seat support, sometimes referred to as the spider, is connected to and supports the chair seat. The seat support is pivotally mounted to the housing with a horizontal axis that is substantially vertically aligned with the vertical posts. The backrest support, also referred to as a backrest upright assembly, is connected to and supports the chair backrest. The backrest support is pivotally connected to the seat support by the vertical post and a forward horizontal axis. One end of the flipper supports the backrest support. In a preferred embodiment, the bearing means is mounted to the backrest support and snugly engages the flipper so that the bearing means can slide across the surface of the flipper as the user leans back and forth. The other end of the flipper is pivotally attached to the fixed housing. The rear part of the seat support is connected to the middle part of the flipper. Thereby, the flipper correlates with the tilt of the seat and the backrest, resulting in substantially greater angular movement and displacement of the backrest than the seat. The resilient biasing means, preferably a torsion spring, biases the chair upright or to a non-tilted position. In a preferred embodiment, the torsion spring has front and rear portions that extend substantially perpendicular to the torsion axis. The rear of the spring contacts the flipper and imparts an upward force on the flipper that biases the chair to an upright position. The front portion of the spring engages and is retained by the tension adjustment bolt. The chair also has a spring mounting assembly for resiliently supporting the front of the seat. The spring mounting assembly preferably includes a pair of compression springs that engage under compression between the underside of the chair seat and the seat support. The backrest support is a pair of substantially vertical members, a horizontal member interposed between the vertical members,
And preferably a pair of substantially parallel horizontal extension arms attached to the ends of the substantially vertical members. The bearing means are attached to the horizontal cross member. The base of the chair is covered by a base cover assembly consisting of upper and lower base covers. The lower base cover has a central portion and a plurality of arms that overlap the radial legs of the base and extend radially therefrom. Each arm has an upwardly extending tab for engaging the upper base cover. The central portion has a generally cylindrical shape forming a generally cylindrical interior and has a radial interior that reduces the cross-sectional area of the interior to allow a friction fit between the lower base cover and the base. It has a protrusion extending toward the side. A rubber ring fits into the space between the base hub and the lower base cover to enable a second friction lock. The upper base cover has a central portion and a plurality of arms extending radially therefrom. Each arm has a downwardly extending holed tongue which, after assembly, accommodates a corresponding upwardly extending tab on each leg of the lower base cover to accommodate the outer end of each leg between the upper and lower base covers. Allows snap fitting. The upper base cover also has a downwardly extending flat surface that aids in the installation of the upper base cover in relation to the base. The central portion of the upper base cover has a generally circular opening for receiving the base. The central portion has tabs extending radially inward from the periphery of the circular opening to allow a friction fit between the upper base cover and the base.

[0006]

1 shows a chair 10 according to an embodiment of the present invention. The chair has a base 12, a vertical support post or bearing 14 supported by the base 12, a seat 16, and a backrest 18. The lower back member 20 is the backrest 18
And the seat 16. The chair control mechanism, generally designated 22 in FIGS. 2-9, is below the seat 16, but is hidden in FIG. 1 by the seat and lower cover panel 24. The lever handle 26 engages a height adjustment lever 27 extending radially from the vertical post 14 and allows the user to adjust the height of the chair. Pull adjustment knob 28
Is user operable and adjusts the pull on the tilt control mechanism to adjust tilt resistance to the chair back and the seat base. The tilt lock lever 29 shown in FIG. 10 can be operated by the user to set the tilt control mechanism to the locked or unlocked position.

The base 12 comprises an upper base cover 30 and a lower base cover 32, which fit together to form a smooth attractive surface as described in detail below. The chair control mechanism 22 includes a housing 34 pivotally mounted in a fixed horizontal position on the vertical post 14, a seat support 36, a back support 38, and a back frame member or flipper 40.
Consists of. The elastic biasing means 42 comprises a coil spring best shown in FIGS.
Installed within 4 and biasing the control mechanism in a direction that maintains the seat and back of the chair in an upright (untilted) position. A J-shaped tension bolt 41 engages the front portion 42a of the spring, projects from an opening in housing 34, and is adjusted by knob 28 for tension control of spring 42. Seat 16 is mounted on and supported by seat support 36. As shown in FIG. 2 and described below, seat support 36 is mounted to fixed housing 34 about horizontal axis A and is substantially centered on vertical post 14.

Referring to FIGS. 4, 8 and 9, seat support 36 includes two substantially parallel horizontal members 48, having front portions 48a, 50a and rear portions 48b, 50b (see FIG. 4).
It consists of 50. The front portion refers to the front portion of the seat pivot axis A, and the rear portion refers to the rear portion of the seat pivot axis A. U
The member 52 of the shaped cross section is the front portion 48a of the horizontal member 48, 50,
It extends between 50a and connects them. A flat rigid horizontal cross member 54 is provided at the rear portion 48b of the horizontal members 48, 50,
It is fixed to 50b. The transverse member 54 is the seat support 3
6 has holes 56 and 58 for receiving bolts (not shown) for fixing the rear portion of the seat 16. Chair back 18
Is mounted to and supported by the backrest support 38. A backrest support 38 is attached to the housing 34 about an axis B in front of the vertical post 14 as a pivot. The backrest support 38 comprises two substantially parallel vertical members 68,70 and two substantially parallel horizontal members or extension arms 72,74. The horizontal member 76 (FIG. 8) is connected to the vertical members 68 and 70. Horizontal member 7
6 provides strength and support to the backrest support 38 and provides a place for mounting the bearing pad means 78. The backrest support 38 is pivotally mounted to the seat support 36 on a pair of pivot studs 79 threaded into nuts 79a, which nut 79a is mounted on the seat support 36 at a horizontal axis B in front of the vertical post 14. Is welded to the sides of the chair (see FIG. 9), approximately below the user's hip joint in a standard seated position on the chair (perpendicular to the hip joint). The rear portion of the backrest support 38 is supported by the flipper 44 at the sliding interface between the bearing pad means 78 and the back plate 44 of the flipper 40.

The flipper 40 has a plate 44 at one end for supporting the backrest support 38 at the sliding interface C. In this embodiment, the support plate 44 is welded to the flipper 40.
Is formed as an extension of. The opposite end 46 of the flipper 40 is attached to the housing 34 about the pivot axis D by a flipper pivot pin 66 (FIG. 9). The flipper also includes a seat support 3 with a pivotal connection E, which is slidable in the center of the flipper, as a pivot.
It is attached to 6. Axle pin 60 is flipper 40
Hole 61 in the seat support 36 (best shown in FIGS. 2 and 3) that extends into the opening in the side flange 40a of the vehicle.
Extends to secure the flipper 40 to the seat support 36 in a slidably interconnected manner. This is a tiltable seat support 3
Vertical two-way support is provided between 6 and the tiltable backrest support 38 and a load transfer relationship is established between them. The torsion spring 42 rests on a shallow groove "nest" plate 43 welded to the inside of the housing 34.
This spring comprises a forearm 42a and a forearm 42b which extends substantially perpendicular to the torsion axis indicated by T in FIG.
(Shown in FIGS. 8 and 9). The rear arm 42b of the torsion spring 42 contacts the ribs 62 embossed downward to apply an upward force to the rear portion of the flipper 40. The front arm portion 42a of the torsion spring 42 engages with and is held by the tension adjustment bolt 41.

The height adjusting lever 27 shown in FIG. 4 is pivotally supported on one side of the fixed housing 34 and selectively operates the pneumatic cylinder 98 for adjusting the height of the chair seat 16 in a known manner. For engaging the control button 97 at the top of the vertical post 14. FIG. 7 is an explanatory view showing the chair control mechanism of the present invention with the chair in the upright position. The seat pivot axis A is substantially centered on the vertical post 14. The back support pivot axis B is at the front of the vertical post 14. The backrest support 38 is supported at C via one end of the flipper 40. The opposite end of flipper 40 is attached to stationary housing 34 about axis D as a pivot. The flipper 40 is also connected to the seat support 36 via a sliding connection E. A torsion spring 42, shown schematically, exerts an upward force on the flipper 40 in a position behind axis D, thereby urging both the seat and the backrest to their forward or "upright" position. FIG. 9 shows an exploded enlarged view of the chair control mechanism 22. FIG. 9 is shown with the horizontal members 72,74 of the backrest support 38 connectable to the vertical members 68,70. The horizontal members 72,74 are welded to the vertical members 68,70 in this embodiment, but other means of connecting the horizontal members to the vertical members, bolting the horizontal members to the vertical members, or of each pair. For example, the horizontal and vertical members may be formed of one piece. Similarly,
Various means may be used for other components as the assembly and attachment.

FIG. 10 shows a spring mounting assembly 80.
It is shown. This spring mounting assembly 80
Is a pair of coil compression springs 82 supported within the U-shaped member 52 and spaced from each side of the seat front-rear centerline.
Have. The spring 82 is compressedly engaged between the underside 84 of the front of the chair seat 16 and the U-shaped member 52 to elastically support the front of the seat. The spring may be maintained in place by engaging a cylindrical projection or button 85 secured to the seat in any suitable position, such as on a mounting plate 86 secured to the seat. A retaining bolt or machine screw 87 extends into a large central opening 88 in member 52 (see FIGS. 4 and 9) and keeps the spring in compression and allows lateral tilting of the front of the seat as described below. It is screwed to the plate 86 in order to do so. An elastic bumper 89 is also fixed to the plate 86 in a line perpendicular to the upper flanges of the seat support members 48 and 50 and acts as a limit stop for this tilting movement. The back of the chair seat bottom 84 is bolted to the horizontal cross member 54 (shown in FIG. 8). The seat bottom portion 84 is formed of an elastic and flexible material such as plywood so that the seat can be tilted forward, backward, sideways, or obliquely according to the user's movement. Seat flexibility is adjusted by rubber bushings in the mounting holes 56, 58 of the rod 54 around each mounting bolt. The tilt lock lever 29 of FIG. 10 controls the tilting capacity of the chair in a manner similar to known methods. In particular, when the tilt lock lever 29 is set to the "locked" position, it penetrates the flipper 40 and the centered hole 91 in the housing 34 and functionally engages both to allow the flipper 4 to move.
0 to prevent tilting with respect to the seat and backrest housing 34. However, the tilt lock lever 29 "unlocks"
When set in the position, the levers 29 are released from their holes to move or tilt the flipper 40 (and subsequently the chair back and seat) with respect to the housing 34.

FIG. 11 is an exploded elevational view of the base support assembly, generally designated 90. The base support assembly 90 includes a rigid multi-arm base 92, a pneumatic cylinder 9 covered by upper and lower covers or fairings 94 and 96, respectively.
8 and a gas cylinder cover assembly 100.
12 to 17, the upper and lower base covers 94 and 96 are fixed to the base 92 by friction fitting means, and the covers themselves are fixed to each other by snap fitting means. When assembled, the top and bottom covers 94, 96 completely hide the base 92 to provide a finished exterior selected independently of the details of the structure. The lower base cover 96 has a short sleeve portion 103 extending inwardly from the distal end and a central cylindrical portion 102 terminating in a compressed inner grip lip or ring 104. The ring 104 is defined by an inwardly exposed inclined surface 104a and a radial surface 104b. After assembly, the compression ring portion 104 friction fits with the base 92. The shape of the ring 104 facilitates a press-fit assembly of the cover with the cylindrical portion of the base 92 and allows subsequent fastening and retention of the lower cover 96 on the base 92. Therefore, the lower elastic ring 106 is frictionally fitted below the base portion 92 and below the radial surface 104b to prevent the lower base cover 96 from dropping, thereby helping to fix the base cover 96 to the base portion 92.

The upper base cover 94 occupies the same space as the lower cover 96 and forms a lid that fits over and mates therewith. After assembly, the top cover has vertical ribs 108 that fit over the arms of the base 92 to position the cover in its regular position relative to the base 92.
The upper base cover 94 has a central opening 110 for receiving the central cylindrical portion 111 of the base 92. After assembly, a plurality of radially inwardly extending cantilever tabs or protrusions 112
Engage the central cylindrical portion 111 of the base 92 in a tight friction fit for positioning or retention. The lower base cover 96 also has upwardly extending resilient latch tabs 114 on each of its radially projecting arms. To engage these tabs 114, each arm of the upper base cover 94 has a downwardly extending resilient taper latch tongue 116 having a hole 118 for receiving and engaging the latch head 120 of each tab 114. Side 120 of the part 120
4 has a shoulder 122 for abutting engagement. In this way, after assembly, the tab 114 is fitted into the hole of the tongue 116 with a hole and snap-fitted. In this aspect, 5
There is a pair of tabs and latch tongues, one pair for each of the five arms. In the assembling process, the upper base cover 94
Is fixed to the base 92 by friction fitting means. The lower base cover 96 is similarly fixed to the base 92 by friction fitting means, and the upwardly extending latch tab 114 engages with the downwardly extending latch tongue 116 of the upper base cover and snaps between the upper and lower base covers. To do. Small washer 12
8 is fitted under the gas cylinder assembly 98 onto the shaft. Clip 130 engages a groove in the shaft. The elastic base ring 106 mates with the base 92 to help hold the lower base cover in place. The casters 126 are installed after the lower base cover is fixed to the base.

Hub liner 132 fits into a central opening in base 92. First large washer 134, bearing 13
6, second large washer 138, and rubber cushion 14
Zeros are respectively interposed between the hub liner 132 and the large diameter portion of the gas cylinder 98. The multi-section telescopic bearing cover 100 fits over the gas cylinder 98, hiding it from sight and making the appearance appealing. Cover 100
A flexible snap tab 101 in the lower end of the mat engages with a hole 105 provided around the center of the upper base cover. The foam filling piece 142 is interposed between the bearing cover 100 and the gas cylinder 98. In operation, referring to FIG. 7, when the user leans back to the chair according to the present invention, the backrest support 38 is urged downwards at the interface C against the flipper 40 to center the flipper 40 about the axis D. To rotate. That is, the flipper 40 is deflected downward at a position inclined to the back. When the flipper 40 is deflected downwards, the seat support 36 rotates about the seat pivot axis A in a predetermined relationship due to vertical interengagement between the seat support 36 and the flipper 40 by the pin 60 in the hole 61. .. Interconnection part E
As a result of the same vertical movement of the flipper 40 and the rear of the seat at, each radius or "link" between DE and AE
The difference in effective length of the flipper 40 causes the angular movement of the flipper 40 to be substantially greater than that of the seat support 36. Similarly,
Due to the fact that the distance between D and C substantially exceeds the distance between D and E (more than twice), the flipper 40 causes the above-mentioned support in the C position to be larger than the rear end of the seat support 36 in the E position. Vertical displacement. As a result, the backrest support 38, and thus the
The chair back 18 correspondingly moves more vertically than the rear of the seat 16. In this regard, the lower back member 20 is also fixed to the supports 68, 70 and moves vertically adjacent thereto with the rear edge of the seat 16.

The torsion spring 42 resists rearward tilting of the chair by applying upward pressure on the flipper 40 at a location 62 where the torsion spring 42 and the flipper 40 contact. The seat support 36, and thus the seat 16, pivots about a seat pivot axis A. The seat pivot axis A is set at an intermediate point between the front part of the seat and the rear part of the seat, so that the seat 16 moves forward by substantially the same distance as it moves downward by the rear. Since the backrest pivot axis B is set on the seat support 36 ahead of the seat pivot axis A, the backrest pivot axis B moves slightly upward when the chair seat and the backrest tilt rearward. The substantial vertical displacement in the C position, which is somewhat compensated for by the upward movement in the B position, is substantially greater than the angular displacement of the seat, for example about 1.5: 1 with its back pivot B about its front pivot B. It is sufficient to pivot 38. This relationship between the chair back and the seat provides a comfortable, ergonomically desirable tilting action.

The beneficial result of the shape and angular and vertical and mutual movements is that the distance between any point on the seat and the lumbar support area of the chair back changes only slightly during the movement. Yes, which minimizes or eliminates the side effect of "shirt pull". According to a particular embodiment, a satisfactory design of the control mechanism 22 of Figure 2 has the following approximate dimensions. A-B = 2.0 inches (5.1 cm) A-D = 2.4 (6.1 cm) A-E = 3.8 (9.7 cm) B-C = 9.0 (22. 9 cm) DC = 4.8 (12.2 cm) DE = 1.5 (3.8 cm) The spring mounting assembly 80 located below the front of the seat 16 has a pressure on the front legs of the user. It compresses as it increases, slightly reducing seat tilt. In this manner, the spring mounting assembly reduces leg pressure due to upward movement of the front edge of the seat 16 and accommodates independent shift movements of the user's legs. It will be appreciated that many modifications are possible in the particular embodiment described above. For example,
The backrest support is pivotally mounted directly to the housing 34. As another aspect, the backrest support frame and the outer end portion of the flipper member and the support 1 are provided.
4, fixed to a pivot axis D which is shifted to the front point, to provide an appropriate interconnection between the flipper and the seat support, whereby the separate connection BC can be omitted. However, the illustrated embodiment is preferred in that it has beneficial effects and can be implemented with relatively simple and economical modifications that have proven and available control mechanisms. Accordingly, the present invention provides a chair that meets the above objectives, as well as a chair that is relatively simple to manufacture, comfortable to use, and attractive in appearance. It is understood that other modifications with respect to details, placement of parts, and assembly procedures based on the above description to illustrate the nature of the invention are possible to those skilled in the art within the spirit and scope of the invention. Let's do it.

[Brief description of drawings]

FIG. 1 is a front perspective view of a chair according to an embodiment of the present invention.

FIG. 2 is a side elevational view of a chair control mechanism according to an embodiment of the invention, shown in a non-tilted position with a partial cross section of the backrest support.

3 is a side elevational view of the chair control mechanism of FIG. 1 shown in a tilted position.

4 is a top view of the chair control mechanism of FIG. 2 with the back support removed.

5 is a side elevational view of the backrest support of FIG.

FIG. 6 is a bottom view of the chair control mechanism of FIG.

FIG. 7 is an illustration showing a chair control mechanism according to the present invention with the chair in an upright position.

FIG. 8 is a front perspective view of the chair control mechanism of FIG.

9 is an exploded perspective view of the chair control mechanism of FIG.

FIG. 10 is a front elevational view of a chair control mechanism according to the present invention showing a spring mounting assembly.

FIG. 11 is an exploded perspective view of a chair base assembly according to the present invention.

12 is a top view of the upper base cover of FIG. 11. FIG.

13 is a top view of the lower base cover of FIG. 11. FIG.

14 is a cross-sectional view of the upper base cover of FIG. 12 taken along line 14-14 of FIG.

15 is a cross-sectional view of the lower base cover of FIG. 13 taken along line 15-15 of FIG.

16 is an enlarged view showing the fitting between the lower base cover and the base of FIG.

FIG. 17 is an enlarged view showing the fitting between the upper and lower base covers shown in FIGS. 14 and 15.

[Explanation of symbols]

 10 ... Chair 12 ... Base 14 ... Vertical post or bearing 16 ... Seat 18 ... Backrest 20 ... Lower backrest member 22 ... Control mechanism (control device) 24 ... Lower cover panel 26 ... Lever handle 27 ... Height adjustment lever 28 ... Pulling Adjustment knob 29 ... Inclined lock lever 30 ... Upper base cover 32 ... Lower base cover 34 ... Housing 36 ... Seat support 38 ... Backrest support 40 ... Flipper or backrest frame member 42 ... Torsion spring (elastic biasing means) 44 ... Back plate 48, 50 ... Horizontal member 54 ... Horizontal cross member 60 ... Axel pin 68, 70 ... Vertical member 72, 74 ... Horizontal member or extension arm 80 ... Spring mounting assembly 84 ... Seat bottom 86 ... Mounting plate 89 ... bumper 90 ... base support assembly 92 ... multi-arm base 94 ... upper base cover Bar 96 ... Lower base cover 98 ... Gas cylinder assembly (or gas cylinder) 100 ... Pneumatic cylinder cover assembly (or cover) 140 ... Cushion

Claims (36)

[Claims] 1. A control device for a chair having a tiltable seat and a tiltable backrest supported on a substantially vertical bearing, said control device comprising a front part corresponding to the front part of the seat to be installed and A control base member having a rear portion on which the chair back is mounted,
And a means for installing the base member on a bearing or the like arranged in a predetermined manner with respect to the horizontal, a first pivot shaft installed substantially below the position of the lumbar joint of the user who is normally seated on the chair in front of the means. A movable backrest support pivotally coupled to the control device for central pivotal movement, the backrest support including a rear portion for vertically supporting a chair back, a second horizontal spacing from a first pivot axis. A movable seat support pivotally coupled to the control device for pivotal movement about a pivot axis, the movable seat support having a rear portion, engaging the backrest support and the seat support, and The seat support seats during the angular movement in which the angular movement of the backrest support is greater than the angular movement of the seat support and an accompanying vertical movement of the rear of the backrest support is applied during such angular movement. The rear part of the vertical movement so as to substantially exceed the,
A movable interconnect for enabling simultaneous joint pivotal movements of the backrest support and the seat support about respective pivotal connections with the control device, and located behind the first pivot axis and A torsion spring that engages at least one of the movable elements adjacent the rear portion thereof and thereby urges the movable elements to an upright position of the backrest and seat when mounted.
Chair control device. 2. The chair control system of claim 1, wherein the movable seat support is pivotally coupled to the base member, and the movable backrest support is pivotally coupled to the movable seat support. 3. The chair control device of claim 2 wherein said second pivot shaft is mounted on said means directly above a vertical support to which said control device is attached. 4. The other movable connection part is pivotally connected to the control device and engages the first engaging part of the movable backrest support and the second engaging part of the movable seat support. A member, wherein the first engaging portion is the second engaging portion of the second engaging portion.
At a distance that substantially exceeds the distance from the pivot axis, the first
4. The chair control device of claim 3, spaced from the axis. 5. The chair control of claim 4, wherein the other movable member is coupled to the controller for pivotal movement about a third pivot axis rearwardly spaced from the second pivot axis. apparatus. 6. The torsion spring is mounted about the third pivot axis and is spaced rearwardly from the third pivot axis for applying a biasing force to bias the movable element to the upright position. 6. The chair control device according to claim 5, wherein the control device engages with the other movable member in a region. 7. A control device for a chair having a tiltable seat and a tiltable backrest supported on a substantially vertical bearing, said control device comprising a front part corresponding to the front part of the seat to be installed and A control base member having a rear portion on which the chair back is mounted,
And a means for mounting the base member on a bearing or the like arranged at a predetermined position with respect to the horizontal, a first pivot installed in front of the means and substantially below the position of the lumbar joint of the user who is normally seated in the chair. A movable backrest support pivotally coupled to the control device for pivotal movement about an axis, the backrest support including a rear portion extending rearwardly from the first pivot axis and vertically supporting a chair back; A moveable seat support pivotally coupled to the controller for pivotal movement about a second pivot axis spaced rearwardly from one pivot axis, the moveable seat support extending rearward from the first portion. And another movable member pivotally coupled to the control device and having a rear end for engaging the first engaging portion of the movable backrest support and the second engaging portion of the movable seat support. One person Parts are the second
Spaced apart from the first axis by a distance that substantially exceeds the spacing of the engagement portion from the second pivot axis so that the angular movement of the backrest support greatly exceeds the angular movement of the seat support. And the other movable member is such that the associated vertical movement of the back of the backrest support during such angular movement substantially exceeds the vertical movement of the rear of the seat on the backrest support during such angular movement. Permitting simultaneous joint pivotal movements of the backrest support and the seat support about respective pivotal connections with the control device, and engaging the other movable member and the backrest. A backrest when attached to each of the support and the seat support, and the other movable member to the upright position of the seat, the backrest support, and an elastic biasing member for biasing the seat support. To, chair of the control device. 8. The chair control of claim 7 wherein said other movable member is coupled to said controller for pivotal movement about a third pivot axis rearwardly spaced from said second pivot axis. apparatus. 9. The other movable member is slidably engaged with each of the backrest support and the seat support, and along which the two supports pivot as they pivot about their respective pivot axes. 9. The chair control device of claim 8, which allows automatic adjustment of the engaged points. 10. The chair control device of claim 9, wherein the engagement of the backrest support with the other movable member is adjacent the distal end of the other movable member. 11. The chair control device of claim 10, wherein the engagement between the seat support and the other movable member is intermediate between the engagement between the back support and the second pivot shaft. 12. The engagement between the seat support and the other movable member is adjacent to the second pivot shaft.
1. Chair control device. 13. The torsion spring is installed about the third pivot axis and is configured to apply a biasing force to bias the movable element to the upright position.
9. The chair control device of claim 8, which engages the other movable member in a region rearward from the pivot axis. 14. A base, a vertical post supported by the base, a chair seat having a rear portion and a front portion, and a tiltable chair having a chair back, mounted on the vertical post installed at a predetermined position with respect to the horizontal. A housing, an elastic biasing means installed in the housing for biasing the chair to an upright position, a seat support connected to and supporting the chair seat, the seat support being the vertical post. A backrest support connected to and supporting the chair backrest, the backrest support being forward of the vertical post, pivotally coupled on the housing for pivotal movement about an axis mounted thereon. One end pivotally coupled on said control device for pivotal movement about the axis of said seat and supporting said backrest support, said seat support The intermediate portion, and characterized in that it consists of back frame member having a pivot coupled the other end to the housing, the chair control device for body and engage. 15. Means for supporting said backrest support on said backrest frame member, having bearing means attached to said backrest support and engaging with said backrest frame member for sliding movement thereon. 15. The chair control device of claim 14, further comprising: 16. The backrest support to a pair of substantially parallel vertical members, a horizontal member interposed between the vertical members having the bearing means attached thereto, and one end of the substantially parallel vertical members. 16. The chair control device of claim 15, comprising a pair of fixed substantially parallel horizontal extension arms. 17. The chair control system of claim 14, wherein the elastic biasing means comprises a torsion spring. 18. The torsion spring has a rear portion extending substantially perpendicular to the torsion axis, the rear portion contacting the backrest frame member and exerting an upward force thereon. 17 chair controls. 19. The seat support is a pair of substantially parallel horizontal members, each horizontal member having a front portion and a rear portion, a U-shaped member extending between and connecting the front portions of the horizontal members, and 15. The chair control device of claim 14, wherein the rigid rigid horizontal cross member is secured to the rear of the horizontal member, the horizontal cross member having holes for receiving bolts. 20. The chair control device further extends into the hole, wherein each of the horizontal members is a hole, the holes being substantially laterally disposed relative to each other and arranged substantially parallel to each other. 20. The chair control system of claim 19 having an axle rigidly attached to said back frame member, said back frame member adapted for sliding engagement with said seat support. 21. The chair control apparatus of claim 20, further comprising a spring mounting assembly mounted within the U-shaped member. 22. A pair of compression springs wherein the spring mounting assembly engages under compression between the underside of the chair seat and the U-shaped member to resiliently support the front portion of the chair seat. 22. The chair control device of claim 21, comprising: 23. The chair control system of claim 14, further comprising a lower backrest assembly interposed between the chair backrest and the chair seat and attached to the backrest support. 24. The vertical post comprises a pneumatic cylinder that enables height adjustment of the chair seat, the chair further mounted on the chair controller and functionally engaged at one end to the pneumatic cylinder. Have a matching lever assembly,
And a second end member extending substantially radially from the vertical post, wherein the lever assembly is configured to allow the pneumatic cylinder to freely adjust the vertical direction in the first position, thereby providing the chair seat. 15. The chair of claim 14 wherein the height of the chair seat is adjusted and the lever assembly is not free to adjust the vertical direction of the pneumatic cylinder in the second position so as to maintain the chair seat at a fixed height. Control device. 25. A chair base base cover assembly having a plurality of radial support legs, the lower base cover having a central portion and a plurality of members extending substantially radially therefrom, wherein the members are remote. A central end having a proximal end, the central portion forming a generally cylindrical interior and including means for enabling a friction fit between the lower base cover and the base; and An upper base cover having a portion and a plurality of members extending substantially radially therefrom, the member having a distal end, the central portion comprising a generally circular opening for receiving in the base;
And means for enabling a friction fit between the upper base cover and the base, wherein the upper and lower base covers fit together along a substantial portion of their radially extending members. A base cover assembly, comprising: 26. The base cover assembly of claim 25, further comprising retaining means located at the distal ends of the radially extending members for securing the upper and lower base covers to each other. 27. The base cover assembly of claim 26, wherein the retaining means enables a snap fit between the upper and lower base covers. 28. The retaining means comprises a latch tab extending substantially upward from the lower base cover and having a side latch surface, and a latch tongue extending substantially downward from the upper base cover, the tongue defining the latch tab. 28. The base cover assembly of claim 27 having a shoulder for receiving and having a shoulder for abutting engagement with a side latch surface of the latch tab. 29. The means of enabling a friction fit between the lower base cover and the base comprises a radially inwardly extending projection that reduces the cross-sectional area of the generally cylindrical interior. Base cover assembly. 30. The means of enabling a friction fit between the upper base cover and the base comprises a plurality of tabs extending radially inward from the perimeter of the generally circular opening. Base cover assembly. 31. A chair base base cover assembly having a plurality of radial support legs, the lower base cover having a central portion and a plurality of members extending substantially radially therefrom. Each of the extending members has an upwardly extending latch tab, the central portion is generally cylindrical forming a generally cylindrical interior, and a radially inwardly extending projection that reduces the cross-sectional area of the generally cylindrical interior. An upper base cover having a central portion and a plurality of members extending substantially radially therefrom, the upper base cover having a central portion and a plurality of members extending radially from the central portion, Each of the extending members has a downwardly extending latch tongue and a downwardly extending substantially flat surface for mounting the upper base cover in position relative to the base, the central portion being the base portion. Comprising a generally circular opening for receiving, and including a tab extending radially inward from the periphery of said opening to allow a friction fit between said upper base cover and said base. A base cover assembly, wherein the plurality of upwardly extending latch tabs are engageable with the plurality of downwardly extending latch tongues to allow a snap fit. 32. A chair seat having a base, a vertical post supported by the base, a seat support, a rear mounted on the seat support and fixed to the seat support, and a spring, and a spring. In a chair having a mounting assembly, the spring mounting assembly under compression between the front of the chair seat and the seat support for elastically supporting the front of the chair seat. A chair characterized by comprising a plurality of engaging compression springs. 33. The chair of claim 32, wherein the seat is formed of a resilient, flexible material. 34. The chair of claim 33, wherein the elastic soft material is plywood. 35. The chair of claim 34, further comprising a rubber bushing between the chair seat and the seat support for adjusting the flexibility of the seat. 36. The chair of claim 35, wherein the rubber bushing is interposed between the back of the chair seat and the seat support.